Rabble-arm for roasting-furnaces.



H. H. STOUT.

RABBLE ARM FOR ROASTING FURNACES.

APPLICATION FILED OCT. 30, 1913- Patented May 23,1916.

WITNESSES afmmw (MM 6%. 91b M 3 I'7 B ATTORNEYS smea HARRY H. STOUT, OF NEW YORK, N. Y., ASSIGNOR TO GENEILAL CHEMICAL COMPANY,

1 OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

' RABBLE-ABM FOR ROASTING-IEURNACES.

areas To allwhom it may concern Be it known that I, HARRY H. STOUT, a

' citizen of the United States, and a resident tain new of the borough of Manhattan, city, county, and State of New York, have invented oer and useful Improvements in Rabble-Arms for Roasting-Furnaces, of

which the following, taken in connection with the accompanying drawings, is a specification. I My invention relates to rabble arms for stirring material on a treating surface and propelling .it over said surface, and has especial application to ore roasting furnaces .of the. general type described in United States Letters Patent to John B. F. Herreshoff, No. 616,926, dated January 3, 1899. In

such furnaces a plurality of superposed ore roasting hearths are provided and rabble arms extending radially from a central rotatable' shaft sweep. over each hearth, their teeth stirring and gradually moving the ore over the hearth toward apertures therein through which the ore falls upon the next lower hearth. These apertures are placed alternately at the centers and the peripheries of the hearths so that ore fed into the top of the furnace is moved outwardly on certain hearths and inwardly on the adjoining hearths, thus traversing the whole furnace until it is discharged through asuitable dis charge aperture at the bottom.

One of the objects of my invention is to. provide a rabble arm construction such that all of the rabble arm'teeth move forwardly equal amounts of ore.

Another object is to provide such a structure that the teeth will pass over substantially the whole area of the hearth during on all portions of the hearth, the ore being in annular piles of substantially equal altitude and base.

, .Other objects will be pointed out or will otherwise appear in the following descrip tion of the embodiment of my invention shown-in the accompanying drawings in.

Specification of Letters Eatent.

Patented May 23, ans.

Application filed 0ctober'30, 1913. Serial No. 798,209.

vice, andFig. 5 is a plan view of the rabble sections lbcated near the line 33 of Fig. 2.

The drawings show a construction adapted tomoye the ore outwardly with respect to the central shaft and adapted to be used in connection with a hearth having peripheral discharge apertures. It will be understood, of course, that a similar construction but with the teeth oppositely disposed, will accomplish a forward movement of the ore in a direction inwardly with respect to the shaft and that such construction is adapted to be used in connection with hearths in which the discharge aperture or apertures are at the center of the hearths.

In the construction shown the rabble arms 1 and 2 are secured at their inner ends in any suitable manner to the central rotatable shaft 4:, it'being understood that the latter may be of any known construction and that it is suitably supported and arranged to be driven in the direction. shown by the arrows in'Fig. 2. The lower portions of the arms are provided with lateral flanges 5, 5' (see Fig. 3) with which the hooked extensions 6, 6 of the toothed-sections 7 engage so that the tooth-sections are secured to and supported by the rabble arms. The tooth sections, as shown, are each provided with two depending teeth 8 and are fastened to the arms by hooking them on the flanges 5, 5 and sliding them inwardly into proper position; inward displacement of the innermost section is prevented by the stops 7'.

One end of eachctooth section is provided with a lug 9 and the other end thereofis provided with a recess into which the lug of the adjoining tooth section is adapted to project. The lugs of the different sections are out of alinement so that, as will readily be understood, it is impossible to assemble the tooth sections in any sequence other than the .proper one. Thus the position of each tooth section as shown upon the arm and the linear order of succession of the teeth are determined by providing theabutting ends or surfaces of the tooth sections with selectively coacting interlocking devices, each of said devices being unlike any other thereof. The outer section is anchored to the rabble arm in any suitable manner as by the bolts 10 to prevent outward movement thereof along the arm.

The meeting faces of the arm and the tooth-sections are provided with a tongue and groove structure 11 which extends longitudinally of the armand is located slightly at one side of the central point between the flanges 5, 5. A similar, tongue and groove arrangement is provided on the rabble arms of the adjoining hearths, but inthis case the tongue and groove is located on the opposite side of the center line of the arm. This device makes it impossible for a tooth section designed to be used for outward propulsion of ore, to be assembled upon a rabble arm designed for a hearth upon which the ore is to be propelled inwardly. The cross sectional configurations of the flanges 5, 5' and the cooperating hooks 6, 6 are such that it is impossible to slide the tooth sections in place unless their ends are pointed in the proper direction. Thus the proper orientation of the teeth along the arm is provided for. As shown particularly in Fig. 3 this is accomplished by beveling the upper surface of the flange 5 and the coacting under surface of the hook 6 while the corresponding faces of the parts 5" and 6' are left unbeveled.

The teeth 8 are provided with a rear or discharge portion 12, adapted to propel the ore forwardly, that is, outwardly on the hearth and a front or entering portion 12 at an angle to the rear portion 12, adapted to propel the ore backwardly, that is, toward, the center of the hearth. It will be seen that the portion 12 is located behind the portion 12 in the direction of their movement due to the rotation of the rabble arm, and that both portions are at an angle to the rabble arm as well as at an angle to one another, and lie on the same side of, and are oppositely inclined to, a line drawn through the vertex of the latter angle in the direction of rotation. The rear portions of the teeth are set at a fixed angle with respect to the rabble arm and are therefore parallel. The angle between the front and rear portions of the teeth, represented by a), Fig. 5, progressively decreases toward the outer end of the arm. The radial projection of the tooth-portion 12 is different for the several teeth of the series, and in general the radial projection of the portion 12. of any tooth diifers from that of the portion 12 of said tooth. Moreover, the free ends of the portions 12 and 12 of each tooth lie at different radial distances from the center of rotation.

With such arrangement of ore propelling and stirring elements, it will be seen that as the arm revolves, the front portions 12 of the teeth will move aportion of the ore backwardly, the amount so moved by each tooth during a given angular movement of the arm, for example, a complete revolution thereof, depending upon the angle of said portion of the tooth and the lineal distance through which the tooth travels; it will be readily understood that the teeth near the outenend of the arm move through 'a greater linear distance than do those near the inner end of the arm. The rear portions 12 of each tooth will move a portion of the ore in like manner but in aforward direction, the amount so moved depending upon the lineal distance through which the tooth travels and also upon the effective area of the portion 12; this effective area depends, in turn, upon the angle 9] between the portions 12 and 12' which when large leaves a large effective area for the rear portion 12 and when small leaves a. small effective area therefor. It will be obvious, of course, that any other suitable form of tooth may be used instead of the specific form shown for accomplishing the outward and inward movement of ore.

Reference to Fig. 4 will make clear the operation of the teeth upon the ore. The teeth of the rabble arms 1 are engagingwith the concentric piles of ore in the positionin which they were left by the previous-passage of the arm 2. These piles are shown by the representation A. The teeth of the arm 2- are engaging with the piles B which are in the position in which the arm 1 by its passage had left them. The front portion 12 of the innermost tooth of rabble arm 1 is effective to move the'ore represented by the cross sectional portion a in a backward direction while the rear portion 12 thereof is effective upon the portion a to moveit A forwardly. It will be seen that the other teeth on the rabble arm 1 move progressively greater cross sectional portions of ore backwardly and smaller portions forwardly, the last tooth being effective upon the areas a and a in backward and forward propulsion respectively.

The portions of ore not moved by the teeth of the arm 1 are acted upon by the teeth of the arm 2.- These teeth are so 10- cated with respectto those of arm 1 as to pass over all portions of the hearth which have notbeen passed over by the teeth of arm 1,.so that in each revolution of the shaft 4, all portions of the ore'have been engagged and moved and the entire area of the hearth has been passed over. ;The teeth of arm 2 are generally similar to. those of arm as being merely a fiat scraper. The second tooth moves the cross sectional portion 5 backwardiy' and the portion F) forwardly and the last or outermost tooth moves the portion 6 backwardly and the portion b forwardly. v

Although the forward propulsion cross sectional areas decrease toward the ends of 1; the innermost tooth is shown, however,

messes the arms, the volume of material moved forwardly tor a given angle of rotation is the same for each tooth, this being due to the fact that where the cross sectional area is smaller the linear travel. of the tooth is correspondingly greater. For instance, the

cross sectional area a multiplied by the i the oaclrward n'ioveu ent of the remaining portions,

all. of the ore being moved in one direction or the other and the entire hearth being passed over by the teeth. The fact that all of the ore is thus moved gives to my invention the important feature that incrustations or, in other words, the formation of the ore into large masses, is eilect'ually prevented. be observed, that the distance between the teeth is substantially the same atoll points. There is thus formed a free passage for the ore between the teeth and injury to the rabble structure due to clogging is avoided.

The piles of ore are all of substantially even and altitude so that bed of ore maybe said to be of substantially even depth over/the entire surface of the hearth The piles, furthermore, present a maximum; surface 'for oxidation, a result which would not obtain it the depth of the ore were less, as is usual with teem of ordinary construction, near the periphery of the hearth. Every particle of ore remains under treatment, substantially the some period. of time and this time is longer with the structure of my in vention than with the ordinary structures heretofore known, Every passage of the rabble arms redistributes the ore uniformly over the hearth, moving a given amount thereof-in the desired direction and discharging it from the hearth at the same rate that the ore to be treated. enters; the apparatus, the ore upon the hearth always undergoing renewed exposure to treatment.

it is to be observed that the material on the hearth flows into a position of repose innnediately site the passage of a tooth, the angle or" reoose varying, of course, acorn-dine; to the nature of the material, I found it advantageous to make the angle which the rear or discharging end of the teeth makes with the center line of the rubble arms greater than the angle of repose of the material undergoing; treatment, preferably about 150?; of such angle of repose. While a prefer the structure described, it

The tooth structure is such, as will,

over a plurality of arms and that various other modifications may be made Without departing from the spirit of my invention as set forth in the appended claims.

I claim:

1. In combination, a rotatable rabble arm and a tooth secured thereto, said tooth being provided with a plurality of operative portions at an angle to each other and located one behind-the other in the direction of rotation.

- 2. In combination, a rotatable rabble arm and a tooth depending" therefrom, said tooth being provided with entering and discharge portions at an angle to the'rabhle arm and at an angle to each other and both of said portions lying on the same side of and being oppositely inclined to a line drawn through the vertex of the latter angle in the direction of rotation. 1

3. ln combinatiomo rotatable rabble arm and a series of teeth secured thereto, said teeth being substantially evenly spaced apart at all points and each of said teeth being'provided with a plurality of operative portions at an angle to each other and located one behind the other in the direction of rotation.

In combination, a rabble arm and a series of teeth depending therefrom, each of said teeth being provided with entering and discharge portions at an angle to each other and to the rabble arm, the discharge portions of the teeth being substantially pan allel to each other.

' 5. in combination, a rotatable rabble arm and a series of teeth dependent therefrom, said teeth being each provided with entering and discharge portions at an angle to each other and to the rub le arm and adapted to move material in opposite radial di rections, both ot' said portions lying on the same side of a hue drawn through the vertex of the angle in the direction of its motion, I

the angles between the teeth portions pro-- gressively increasing toward the outer end of the arm, whereby the resultant amount of. material moved by the teeth in one of said radial directions is substantially the same in quantity for each tooth.

6. In combination, a movable member, a plurality of rubble arms supported thereby and a series of teeth depending from each rabble arm, each of said teeth being provided with'entering and discharge portions at an angle to each other and to the rabble arm said entering portion being adapted to move material in one direction and said discharge portion being adapted to move material in another direction, the teeth of any of said arms having locations thereon'cor-- responding with the spaces between the teeth on the remaining arms, and the width of the spaces between the teeth on any arm be in substantially equal to the effective width we of the corresponding teeth on the remaining arms.

7. In combination, a'rotatable rabble arm and a tooth. secured thereto, said tooth being provided with a plurality of operative portions located one behind the other in the direction of rotation and at an angle to each other, the free ends of said portions lying at different radial distances from the center of rotation.

8. In combination, a rotatable arm and a series of teeth secured thereto, each of said teeth being provided with a plurality ot operative portions at an angle to each other: and to the arm, said portions having unequal radial projections and one of said portions having a radial projection which is different for the several teeth of the series.

9. In combination with a roasting furnace having a series of superposed hearths, a rotatable shaft and a plurality of rabble arms operating on said hearths, said arms being secured to said shaft and provided with tooth securing means which are identical for all the arms, and also provided with tooth directioning means for determining the direction of the teeth relative to their line of travel, the tooth directioning means for an arm operating on one hearth being unlike the tooth directioning means for an arm operating on an adjacent hearth.

10. In combination, a rabble arm and a series of tooth-sections secured thereto in abutting relation, the abutting ends of the tooth sections being provided with coacting interlocking devices, each of said devices being unlike any other thereof, whereby the position of each tooth section when operatively assembled upon the arm "is determined.

11. In combination with a roasting furnace having a series of superposed hearths, a rotatable shaft and a plurality of rabble arms operating on said hearths, said arms being secured to said shaft and provided with tooth securing and (lirectioning means, the latter means determining the direction of the teeth relative to their line of travel, said tooth directioning means for an .arm operating on one hearth being unlike the tooth direetioning means for an arm operating on an adjacent hearth.

12. In combination with a series of rabble arms, a series of unlike rabble teethdetachably secured thereto, and means on each tooth whereby its position and orientation on a predetermined arm, is determined prior to and independently of such assembling 13. In combination with a rabble arm, a series of detachable rabble teeth, securing means upon said arm engaging means upon said teeth tosecure said teeth to said arm in predetermined orientation along the arm; means upon each tooth engaging means upon an adjacent tooth locking said teeth together and determining the linear order of succes-.

sion in which the teeth of a set upon the rabble arm.

14. In combination with a set of rabble arms comprising inwardly and outwardly raking rabble arms, means upon said inwardly raking rabble arms engaging means upmgrabble teeth to secure the same upon said arms in predetermined orientation along the arm, differently constructed means upon said outwardly raking rabble arms engaging corresponding means upon other teeth to secure the same upon said arms. in such manner that each tooth is attached to an arm of a predetermined one of the two above-mentioned sets.-

15. In combination with a set of rabble arms comprising inwardly and outwardly raking rabble arms, means upon said inwardly raking rabble arms engaging means upon rabble teeth to secure the same upon said arms in predetermined orientation along the arm, differently constructed means upon said outwardly raking rabble arms engaging eorresponding means upon other teeth to secure the same upon said arms, in such manner that each tooth is attached to an arm of a predetermined one of the two above-mentioned sets, means upon each tooth engaging locking meansupon an adjacent tooth and determining the linear order of succession in which the teeth are attached to each rabble arm.

16. In combination with a rabble arm for roasting furnaces, a series of rabble teeth, and selectively coacting butt-surfaces on said teeth contacting when the teeth are operatively assembled on said arm, wherebythe order of succession of said teeth on said arm when so assembled is determined.

In testimony whereof, I have hereunto set my hand in the presence of two subscribing witnesses.

HARRY H. STOUT.

are strung Witnesses:

JOHN A. FERGUSON, FRED. A. KLEIN. 

